What Is Cardiac Arrest? What to Know About Why LeBron James’s Son Bronny Collapsed.

LeBron “ Bronny” James Jr., the 18-year-old son of basketball star LeBron James, suffered cardiac arrest on Monday while practicing at the University of Southern California. 

He was taken to a local hospital for treatment, a spokesman for the James family said, and as of Tuesday morning, was stable and no longer in the intensive-care unit.

An incoming freshman at USC, Bronny James is slated to join the Trojans basketball team this fall. Bronny James is the second USC basketball player to suffer a cardiac arrest on campus in recent years, after Vince Iwuchukwu went into heart failure during practice last summer. 

What happened to Bronny James?

More details about Bronny James’ cardiac arrest have yet to be made public. But a report from TMZ said he was transported after the episode to the hospital from USC’s Galen Center, the indoor arena where the Trojans’ basketball team practices and plays. 

What is cardiac arrest?

Cardiac arrest occurs when the heart suddenly stops pumping blood, said Dr. Nahush Mokadam, a cardiac surgeon at the Ohio State University Wexner Medical Center.

Hypertrophic cardiomyopathy, a condition in which the heart muscle becomes abnormally thick, is a leading cause of cardiac arrest in younger people, Mokadam said. 

A range of conditions can lead to cardiac arrest, including abnormal heart rhythms, or arrhythmias, which can be triggered by cardiomyopathy and other heart defects, heart damage and certain medications, cardiologists said. Rarely, cardiac arrest can be triggered by a forceful strike to the chest at precisely the right moment—a phenomenon known as commotio cordis. 

In January, Buffalo Bills safety Damar Hamlin suffered cardiac arrest during a National Football League game after being struck hard in the chest. Hamlin, then 24, collapsed on the field after tackling a player on the opposing team. He has since recovered and has been cleared by doctors to play football again.

Does working out increase risk of cardiac arrest?

Exercise is good for the heart and won’t cause cardiac arrest in most healthy people, said Dr. Mitchel Alpert, the chief of pediatric cardiology at K. Hovnanian Children’s Hospital in New Jersey. But in people with underlying heart conditions, the stress of exercise or other exertion could trigger a cardiac event, he said. 

“Competitive sports are at an entirely different level. If you are prone to having an event, it will bring it out,” Alpert said.

Commotio cordis could also occur during sports. A baseball hitting a player over the heart, a hard tackle or even a strong elbow to the chest could potentially trigger cardiac arrest, cardiologists said, though the odds of its happening are very slim. The force of the impact on the heart needs to be strong enough and must happen at exactly the moment when the heart is resetting itself—a window that can be as short as 30 milliseconds, cardiologists said. But if these factors align, the impact could cause the heart to beat irregularly.

Severe dehydration, which could occur in people who are exerting themselves in hot conditions, can also cause cardiac arrest. Public-health experts have been warning people to keep cool and hydrated amid ongoing heat waves across the U.S. and elsewhere in the Northern Hemisphere. 

How is heart attack or heart failure different from cardiac arrest?

Heart attack and heart failure can lead to cardiac arrest, but are separate conditions, cardiologists said. A heart attack occurs when blood flow, which carries oxygen, to the heart muscle is reduced or stopped. It is usually caused by blockages in the coronary arteries. Symptoms of a heart attack can include chest pain, shortness of breath and pain in the arms and back. Every year, about 800,000 people in the U.S. have a heart attack, the Centers for Disease Control and Prevention said.

Heart failure is a chronic and progressive condition in which the heart can’t effectively pump blood around the body. Possible contributors include buildup in the coronary arteries, previous heart attacks, high blood pressure, obesity, congenital defects, lung disease and diabetes, cardiologists said. More than six million people in the U.S. live with heart failure, according to the CDC.

What are the symptoms of a cardiac arrest?

If a heart attack, heart failure or other underlying heart problem leads to cardiac arrest, a patient could experience symptoms such as shortness of breath, dizziness and chest pains before the event, cardiologists said. But cardiac arrest itself is sudden and characterized by abrupt collapse and loss of consciousness. A person in cardiac arrest will have no pulse and won’t be breathing. 

What are the risks for cardiac arrest?

Cardiac arrest is often fatal. Fewer than 12% of people who have a cardiac arrest outside of a hospital survive, according to the American Heart Association. 

Cardiologists said immediate medical intervention is critical for a person who has suffered a cardiac arrest. A defibrillator, a device that delivers an electric shock to the heart and can restore a normal heartbeat in patients, should be used as soon as possible, experts said. While waiting for a defibrillator to arrive, CPR should be administered. Chest compressions can help to manually circulate blood, which can be lifesaving to a person whose heart isn’t beating properly. 

“You can take someone who would’ve died and bring them back,” said Dr. Harlan Krumholz, a Yale University cardiologist.

It isn’t yet publicly known whether Bronny James was treated with CPR or a defibrillator, but cardiologists who weren’t involved with his care said he must have been promptly treated to have survived cardiac arrest. In Damar Hamlin’s case, emergency personnel immediately provided CPR and used a defibrillator to revive him.  

Depending on how long it takes to restore a normal heartbeat and how starved of oxygen the body is, survivors can recover completely from cardiac arrest or suffer from damage to the brain and other organs.

Krumholz said Bronny James’s cardiac arrest should serve as a reminder that everyone should learn how to administer CPR and use an AED, or automated external defibrillator.

“This is a wake-up call of how effective CPR and AEDs can be,” he said.

Write to Dominique Mosbergen at [email protected]